|
Faunsdale, AL | While there are probably better compressors than the A-6 design that was original equipment. A good one will do a good job on R134a
Main thing to do is to clean, clean and clean again. If your condenser is clogged or the fins are bent so airflow is compromised or the evaporator is full of dust, you aren't going to get good performance out of anything. Then if you will flush the system completely to remove excess oil, you will have a better chance of a successful conversion.
I don't always change the expansion valve, but I know some do. I do check the inlet screen in it for debris when I flush the lines. These tractors are old enough, I have had to damage the equalizer line that comes off the expansion valve to get it off the port it screws onto, so best to leave that one alone unless you're going to replace the expansion valve. The main thing is to remove the large connections to the expansion valve so you can flush back through the line coming to it from the receiver/dryer. Which you must remove and replace with new when finished flushing. Then flush through the evaporator and back down to the compressor. From the compressor discharge line, you can flush through the condenser and out the connection where the receiver/dryer has been removed.
Did I mention that you cannot flush a compressor, receiver/dryer or expansion valve. System must be broken down into the sections between these components and flushed. I have used mineral spirits or gasoline followed by compressed air to flush systems, being very cautious about sources of ignition and working outside only. Or you can purchase a bottle of the proper flush that won't do diddly squat to flush such a big system! If you go that route, get a couple of them! Once you have blown several ounces of solvent through the lines, repeated this a few times and then blown with lots of (DRY) air, you can reconnect everything with new green o-rings and vacuum the system. No need to replace o-rings you did not disturb, but do replace any you remove the connection on.
Charge R134-a until you get the low side pressure in the 22 to 25 psi range on a hot day with the tractor running at a fast idle. You may not clear the sight glass by getting to this pressure. I think the head pressure will be lower than if you always charge enough to clear the sight glass completely.
Or you could just slap another compressor on it that has ester oil in it, change the receiver dryer, vacuum it, recharge it and hope for the best. Most of them cool pretty well even with this minimal approach.
One thing that occurs pretty frequently is the steel suction line under the cab will rust out from sweating inside the foam insulation that comes on it from the factory. I have replaced these with factory lines (remove the foam in my opinion) and also with a hose running from the compressor back up to the joint at the left rear corner of the cab. Hose is a lot easier and does away with the potential leak at the disconnect as well as the rusting sweating line.
Edited by ccjersey 3/31/2012 23:54
| |
|
NEED AC 90°F, Switching R-12 to R-134 question
